BUILD STAGE II: LIZARD SKIN INSULATION
The Toyota Land Cruiser HJ75 Troop Carrier is a legend amongst classic 4x4s. It’s reputation has been hard won throughout every corner of the globe. Troopy fans will regale listeners with tales of their epic durability, unrivaled reliability, and pure workhorse attitude. It’s a pretty convincing package considering the number of expeditions the platform has under its belt. What people generally fail to mention though is their comfort.
It shouldn’t come as a surprise that a vehicle such as this would shed all forms of comfort in support of its utilitarian design. In general, such luxuries serve only to hinder a vintage 4x4’s dependability. Olivia and I knew our Troopy had some shortfalls when we bought it last year, but it took us a few months to truly come to terms with them. After a handful of road trips, we began realizing just how loud our vehicle was.
This 1985 Australian Land Cruiser had a heart transplant when it was imported to the U.S. It’s stock 2H engine was replaced with a Toyota 12H-T turbo diesel. Though this “new” engine was only three years younger, it had half the number of miles and provided a much needed boost in performance. The 12H-T is a rather noisy engine and it pairs poorly with the lack of proper insulation in the vehicle.
Our solution to this problem was to apply Lizard Skin spray on Sound Control and Ceramic Insulation. Both products are applied with a paint gun, provide a vapor barrier, and don’t retain moisture when they get wet. They are also suitable for use on the underside of the hood. We chose this route over butyl insulation due to the condition of the butyl mat already installed in the cargo area of the Troopy. This adhesive sound control mat had deteriorated into a sticky, messy goo in just two years of light use. It also allowed rust to grow unnoticed for the first year of our ownership.
The ability to have thermal insulation in our vehicle without the moisture retaining nature of wool, and recycled denim has provided significant peace of mind. At 35 years old, our Troopy is at high risk of developing even more rust. After patching a handful of holes and inhibiting surface rust we found under the butyl, if felt good to know the Lizard Skin would protect from further oxidation.
The application process was straightforward and easy. We prepared the surfaces by cleaning them with a gunk remover and vacuuming up the remnants of welding and grinding. After covering up bolt holes and wires we were ready to begin. I started by mixing the first two gallon bucket of Sound Control. When using both products it is crucial that the Sound Control is applied before the Ceramic Insulation. This allows them to properly work together.
Spraying the transmission cover was the only difficult portion of the application process; it was the test dummy and I wasn’t quite sure how the spray pattern would turn out. After that, it was about as easy as one could hope for. The Troopy has multiple hard to reach areas on the interior walls, but a spray on application made them a breeze to get to. When I pulled the butyl mat off these same areas it was easy to see the difficulty of cutting shapes and sizes without a clear picture of the dimensions.
The application process took two days and required four gallons of each product. We sprayed two coats of each insulator for a total of four coats. Cleaning up was a breeze and there was very little overspray. Other than the few areas I taped off, if I wanted to keep an area from being sprayed I simply used a bit of cardboard to block off the area.
The hood is what I had been most excited to insulate. This oil stained surface had the potential to be our best defense against engine noise. Instead, it rattled and allowed the engine noise to transmit unchecked. Even something as simple as closing the hood after an oil check would leave my ears ringing. This was the first thing I tested after the Lizard Skin had fully cured. Closing the hood from the same height is now a much nicer experience. Rather than the previously drawn out reverberations, we had a solid clunk and then silence. Even popping the hood latch had a higher end feel to it.
To put it to the test we immediately embarked on a thousand mile road trip, driving the entire length of the Oregon Coast and hundreds of miles on an interstate highway. Over the course of the three day trip, 28 hours were spent behind the wheel. The overwhelming feeling Olivia and I had on this trip was astonishment at how much quieter the interior of the vehicle was. As soon as we started accelerating to highway speeds we knew we were in for a significantly improved driving experience.
In the past, driving above 40MPH rendered conversations quite challenging over top of the noise of the Toyota 12H-T diesel engine and the lowered windows. On this trip, however, we were able to talk in almost normal voices and listen to music at an appropriate level. Having the windows down was no longer the “final straw” that tipped us over the downhill slope of driving fatigue. The heat levels in the vehicle had also improved. Not only were we more comfortable, but the ceramic was blocking enough heat to prevent our Goal Zero Yeti 1000 from turning on its cooling fan in the near-90℉ weather. There were numerous times on this trip that I looked over to Olivia and commented on how amazed I was at the improvement.
When I had finished spraying the Lizard Skin in the cab, I remember standing at the back of the vehicle looking at the newly applied surface. Just two weeks prior it had been rusted out and covered in melted rubber. Now we had a polished, professional look that performed far better than Olivia and I could have expected. Every vehicle build has a few pivotal moments, and this was one of ours.
